Forensic Toxicology

Poison is any substance that can harm or kill and Toxicology is the study of it. Forensic Toxicology study postmortem signs of the poisoning. The toxicity of a substance depends on the amount ingested, as well as the age, weight and state of health of the person who ingests it. Poison can be administered by ingestion, injection, or absorbed through the skin.

Some poisons, such as snake venom, is only dangerous if it is absorbed in the bloodstream. If poison is suspected at a crime scene the first step would be to take a sample from the victim, say from their bloodstream. As there would be other bodily fluids taken, the sample is treated to extract and purify the poison.

Toxicology is the science of adverse effects of chemicals on living organisms. In general, a toxicologist detects and identifies foreign chemicals in the body, with a particular emphasis upon toxic or hazardous substances. A descriptive toxicologist performs toxicity tests to evaluate the risk that exposure poses to humans.

A mechanistic toxicologist attempts to determine how substances exert deleterious effects on living organisms. A regulatory toxicologist judges whether or not a substance has low enough risk to justify making it available to the public. A toxin is any material exerting a life threatening effect upon a living organism. Poisons are a subgroup of toxins.

Toxic materials exist in many forms (gaseous, liquid, solid, animal, mineral, and vegetable), and may be ingested, inhaled, or absorbed through the skin. Poisons generally enter the body in a single massive dose, or accumulate to a massive dose over time. Toxins work in minute quantities or low levels, requiring sensitive analytical instruments for detection.

Some toxins have medicinal value, but many produce irreparable damage. Some toxins have antidotes and others do not. Poisons can be combated by prompt treatment, and most organ damage (except for serious CNS injury) may be repairable. Whereas poisons are somewhat easily identifiable by their symptoms, many toxins tend to disguise or mask themselves.

A forensic toxicologist must consider the context of an investigation, in particular any physical symptoms recorded, and any evidence collected at a crime scene that may narrow the search, such as pill bottles, powders, trace residue, and any available chemicals. Provided with this information and samples with which to work, the forensic toxicologist must determine which toxic substances are present, in what concentrations, and the probable effect of those chemicals on the person.

Some poisons can be extracted using organic solvents, such as ether or chloroform. Chromatography is a technique that separates the various compounds in a sample, and is very useful when it comes to identifying poisons. Nowadays chromatography is coupled with a technique called mass spectrometry.

Another way to identify poison is immunoassay. This is identifying antibodies made up for the foreign bodies in the blood, such as the poison. However this method is still being developed so is not widely used.

If a body suspected of poison has be exposed to nature and insects have been feeding off the body, there may be no or few soft tissues left. If the insects are still at the scene we can dissect them and extract the ingested tissues from their body. The poison may then be extracted from this.

Our Forensic Toxicology service investigates, quantifies and interprets the presence of drugs or poisons in biological samples for legal purposes:-

Helping to establish cause of death as part of a criminal investigation or Inquest.

Quantifying the levels of any alcohol or drugs in blood or urine in cases of alleged drink/drugs driving.

Determining adherence to a mandatory drug treatment program.We work closely with lawyers,police & pathologists and have established specific protocols and reporting formats to ensure that our service is precisely aligned with our clients’ requirements and the legal process, with full chain of custody in place.Should court attendance be requested, all results are legally defensible and incorporated within an Expert Opinion, supported by our well experienced Expert Witness service.

We provide consultation, information and instructional services in matters related to toxicology, drug identification and chemical analysis in the following areas:-

Criminal Matters.

Civil Proceedings.

Employment Arbitration.

Occupational Health and Safety.

Equipment and Method Evaluations.

Employee Assistance Programs.

Regulatory Programs.

Public Safety.

Advisory Role to Government, Industry and the Public.

Alcohol consumption.

Establishment of a pharmacological profile for a subject under given conditions of alcohol consumption.

Assessment of the ability to provide breath samples using “approved screening devices” and “approved instruments” set out in the Criminal Code of India.